CN113775488A

CN113775488A - Cooling system and wind generating set

Info

Publication number: CN113775488A
Application number: CN202010516556.1A
Authority: CN
Inventors: 王丁会; 方涛; 李金梦
Original assignee: Xinjiang Goldwind Science and Technology Co Ltd
Current assignee: Xinjiang Goldwind Science and Technology Co Ltd
Priority date: 2020-06-09
Filing date: 2020-06-09
Publication date: 2021-12-10
Anticipated expiration: 2040-06-09
Also published as: CA3177831A1; AU2020452638A1; EP4130467A4; BR112022023958A2; US20230228251A1; CL2022003357A1; WO2021248717A1; EP4130467A1

Abstract

The invention relates to a cooling system and a wind generating set. The cooling system comprises a first cooling circuit, a second cooling circuit, a third cooling circuit, a first heat exchanger and a second heat exchanger, wherein the first cooling circuit comprises a first fluid pipeline and a first pump group, the second cooling circuit comprises a second fluid pipeline and a second pump group, and the second fluid pipeline comprises a main pipeline and a bypass; the third cooling circuit comprises a third fluid line and a third pump group, the third fluid line simultaneously communicating the first heat exchanger and the second heat exchanger; the first heat exchanger is configured to thermally couple the first cooling medium, the second cooling medium, and the third cooling medium in isolation from one another; the second heat exchanger is configured to thermally couple the second cooling medium and the third cooling medium in isolation from each other by a bypass. The invention realizes the reasonable distribution of cold quantity and the reasonable application of waste heat through the mutual isolation geothermal coupling among the cooling loops, thereby realizing the balanced utilization of cold and heat and reducing the power consumption of the system.

Description

Cooling system and wind generating set

Technical Field

The invention relates to the technical field of wind power generation, in particular to a cooling system and a wind generating set.

Background

In recent years, wind turbine generators are gradually moving toward high power density, the loss of the wind turbine generators is increased, and the number of parts requiring heat dissipation is also increased. The normal operation of heating components such as a generator, a shafting, a variable pitch propeller, a cabin cabinet, a cabin, a converter cabinet, a transformer and the like can be realized only by carrying out necessary heat dissipation and cooling treatment, and particularly for an offshore wind generating set, the E-TOP structure which uniformly arranges the heating components in the cabin is adopted, so that the composition and the layout of a cooling system of the whole unit in the cabin are more and more complex. Therefore, a more compact cooling system layout is required in the limited space of the nacelle, and the design of an integrated cooling system is an important research direction.

Disclosure of Invention

The invention aims to provide a cooling system and a wind generating set, wherein the cooling system can realize balanced utilization of cold and heat and reduce the power consumption of the system.

In one aspect, the present disclosure is directed to a cooling system including a first cooling circuit, a second cooling circuit, a third cooling circuit, a first heat exchanger, and a second heat exchanger; the first cooling circuit comprises a first fluid line for cooling the first heat-generating component and a first pump stack configured to circulate a first cooling medium in the first fluid line; the second cooling circuit comprises a second fluid circuit for cooling the second heat generating component and a second pump group, the second fluid circuit comprising a main circuit and a bypass; the second pump group is configured to circulate the second cooling medium in the main path or in the main path and the bypass; the third cooling circuit comprises a third fluid line for cooling a third heat generating component and a third pump stack configured to circulate a third cooling medium in the third fluid line, the third fluid line communicating the first heat exchanger and the second heat exchanger simultaneously; the first heat exchanger is configured to thermally couple the first cooling medium, the second cooling medium, and the third cooling medium in isolation from one another; the second heat exchanger is configured to thermally couple the second cooling medium and the third cooling medium in isolation from each other by a bypass.

According to one aspect of the present invention, a bypass regulating valve is provided on the bypass, and when the temperature of the third cooling medium is lower than a preset temperature, the bypass regulating valve is opened to allow the second cooling medium in the bypass to exchange heat with the third cooling medium through the second heat exchanger.

According to one aspect of the invention, the first heat exchanger comprises a first heat conduction channel, a second heat conduction channel and a third heat conduction channel which are arranged at intervals; the first heat conduction channel comprises a first inlet end and a first outlet end, a first water supply pipe of the first fluid pipeline is connected with the first inlet end, and a first water return pipe is connected with the first outlet end; the second fluid pipeline comprises a second inlet end and a second outlet end, a second water supply pipe of the second fluid pipeline is connected with the second inlet end, and a second water return pipe is connected with the second outlet end; the third heat-conducting channel includes a third inlet end and a third outlet end, the third fluid conduit includes a first segment and a second segment extending between the first heat exchanger and the second heat exchanger; the third pump group is located in the first section, the upstream of the first section is connected with the third inlet end, and the downstream of the second section is connected with the third outlet end.

According to one aspect of the invention, the second heat exchanger comprises a fourth heat conduction channel and a fifth heat conduction channel which are arranged at intervals; the fourth heat conduction channel comprises a fourth inlet end and a fourth outlet end, a second bypass water supply pipe of a bypass of the second fluid pipeline is connected with the fourth inlet end, and a second bypass water return pipe of the bypass is connected with the fourth outlet end; the fifth thermally conductive path includes a fifth inlet end to which the downstream of the first segment of the third fluid conduit is connected and a fifth outlet end to which the upstream of the second segment is connected.

According to one aspect of the invention, a plurality of first fluid branches corresponding to a plurality of first heating components one to one are arranged on a first fluid pipeline, a first branch radiator is arranged on each first fluid branch, a first branch regulating valve, a first branch temperature sensor and a first branch flow sensor are arranged at the downstream of each first fluid branch, and a first heat radiating unit is further arranged on a first return pipe of the first fluid pipeline; and monitoring the measurement values of the first branch temperature sensors and the first branch flow sensors, and regulating the flow of each first fluid branch by controlling the opening degree of each first branch regulating valve according to the target temperature value of each first heating component.

According to one aspect of the invention, at least one of the first water supply pipe and the first water return pipe of the first fluid line, the outlet of the first pump set and the upstream and downstream of each first fluid branch is provided with a first valve; at least one of the first pump group, the first fluid pipeline and each first fluid branch is also provided with a first drainage valve; the first heat dissipation unit is provided with a first exhaust valve.

According to one aspect of the invention, at least one of the inlet and outlet of the first pump group, upstream and downstream of each first fluid branch, is provided with a first pressure monitoring device.

According to one aspect of the present invention, a plurality of second fluid branches corresponding to the second heat generating components are provided on the main path of the second fluid pipeline, a second branch radiator is provided on each second fluid branch, and a second radiating unit is further provided on the main path near the second outlet end; the main path is also provided with a second total flow sensor positioned at the inlet of the second pump group, a second front total temperature sensor positioned at the outlet of the second pump group, a second middle total temperature sensor positioned at the downstream of the plurality of second fluid branches, and a second rear total temperature sensor positioned at the inlet of the second heat dissipation unit.

According to one aspect of the invention, the total heat dissipation loss of the second fluid pipeline is obtained according to the temperature difference value of the second middle total temperature sensor and the second front total temperature sensor and the flow of the second total flow sensor; according to the temperature difference value between the second rear total temperature sensor and the second middle total temperature sensor and the flow of the second middle total flow sensor, obtaining a heat generating component to be subjected to heat dissipation loss before the second fluid pipeline enters the second heat dissipation unit; and obtaining the residual heat quantity transferred from the bypass to the third cooling loop according to the difference value between the total heat dissipation loss quantity and the heat generating component to be subjected to heat dissipation loss quantity.

According to one aspect of the invention, at least one of the second inlet port, the second outlet port, the outlet of the second pump group, the upstream and downstream of each second fluid branch, the upstream and downstream of the bypass, and the inlet of the second heat dissipating unit is provided with a second valve; at least one of the second fluid pipeline, each second fluid branch and each second branch radiator is provided with a second liquid discharge valve; at least one of the second pump group, the second fluid pipeline, the second heat dissipation unit and each second branch radiator is provided with a second exhaust valve.

According to one aspect of the invention, at least one of the inlet and outlet of the second pump group, downstream of the plurality of second fluid branches and upstream and downstream of the bypass is provided with a second pressure monitoring device.

According to one aspect of the invention, a third total flow sensor is arranged upstream of the first section of the third fluid line, a third front total temperature sensor is arranged downstream of the first section, and a third heat dissipation unit is arranged downstream of the second section; a plurality of third fluid branches which correspond to the third heat-generating components one to one are arranged on the second section, a third branch radiator is arranged on each third fluid branch, and a third branch regulating valve, a third branch temperature sensor and a third branch flow sensor are arranged at the downstream of each third fluid branch; and monitoring the measured values of the temperature sensors of the third branches and the flow sensors of the third branches, and regulating the flow of each third fluid branch by controlling the opening of the regulating valve of each third branch according to the target temperature value of each third heat-generating component.

According to one aspect of the invention, a heater is provided downstream of the first section of the third fluid conduit, the heater being activated when the temperature of the third cooling medium is below a predetermined temperature and the second heat generating component is not activated.

According to one aspect of the present invention, a third intermediate total temperature sensor is further provided upstream of the second section, and the opening/closing of the heater and the opening of the bypass regulating valve are controlled based on a measurement value of the third intermediate total temperature sensor.

According to one aspect of the invention, a third rear total temperature sensor is further arranged downstream of the second section, and the total heat generation amount of the third heat generating component is obtained according to the temperature difference value between the third rear total temperature sensor and the third middle total temperature sensor and the flow rate of the third total flow rate sensor; and obtaining the heat exchange quantity of the third cooling medium after flowing through the first heat exchanger according to the temperature difference value between the third rear total temperature sensor and the third front total temperature sensor and the flow quantity of the third total flow sensor.

According to an aspect of the present invention, at least one of the upstream and downstream of the first section, the upstream and downstream of the second section, the upstream and downstream of each third fluid branch, and the inlet of the third heat radiating unit is provided with a third valve; at least one of the first segment and each third fluid branch is provided with a third drain valve; at least one of the third pump set, the third heat dissipation unit and each third fluid branch is provided with a third exhaust valve.

According to one aspect of the invention, at least one of the inlet and outlet of the third pump stack, downstream of the first section, upstream of the second section and upstream and downstream of each third fluid branch is provided with a third pressure monitoring device.

According to one aspect of the invention, the first pump set, the second pump set and the third pump set respectively comprise one pump body or at least two pump bodies arranged in parallel, each pump body is provided with an exhaust valve, an outlet of each pump body is respectively provided with a check valve, and an inlet of each pump body is respectively provided with a pump body regulating valve; and the inlets of the first pump group, the second pump group and the third pump group are respectively provided with a pressure stabilizing device.

In another aspect, the present invention further provides a wind turbine generator system, including: the first heating component comprises at least one of a shafting, a cable, a cabin, a variable pitch, a cabin cabinet body and a cabin base; a second heat generating component comprising a generator; a third heat generating component comprising at least one of a transformer, a current transformer, and an auxiliary transformer; a cooling system as any one of the preceding.

The invention provides a cooling system, which comprises a first cooling loop, a second cooling loop and a third cooling loop which operate independently, and a first heat exchanger and a second heat exchanger, wherein a first cooling medium in the first cooling loop, a second cooling medium in the second cooling loop and a third cooling medium in the third cooling loop are mutually isolated and thermally coupled through the liquid-liquid three-way first heat exchanger. On the other hand, under appropriate ambient temperature conditions, when the temperature control demand of the first heat-generating component of the small-capacity cooling system is satisfied, the first heat exchanger can distribute the surplus cooling load of the first cooling circuit to the generator cooling system of the second cooling circuit and the electric cooling system of the third cooling circuit, thereby achieving the full utilization of the cooling capacity. In the second aspect, for the generator cooling system, surplus cold energy from the small-capacity cooling system is absorbed through the first heat exchanger, and therefore the over-generation of the unit is achieved or the frequency conversion energy conservation of a rotating component at the tail end of the unit is achieved. In a third aspect, the first heat exchanger is used to achieve thermal equilibrium among the small-capacity cooling system, the generator cooling system, and the electrical cooling system. Meanwhile, through the liquid-liquid two-way second heat exchanger, the second cooling medium in the bypass of the second cooling loop and the third cooling medium in the third cooling loop are mutually isolated and thermally coupled, so that part of residual heat carried by the second cooling loop is used for heating the third cooling loop, and the reasonable application of the residual heat is realized. The cooling system meets the heat dissipation requirement, realizes the balanced utilization of cold and heat through mutual isolation and geothermal coupling among cooling loops, and reduces the power consumption of the system.

Drawings

Features, advantages and technical effects of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings. In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

FIG. 1 is a simplified structural schematic diagram of a cooling system of a wind turbine generator system according to an embodiment of the present invention;

FIG. 2 is a schematic diagram of a first cooling circuit in the cooling system of FIG. 1;

FIG. 3 is a schematic diagram of a second cooling circuit in the cooling system of FIG. 1;

fig. 4 is a schematic configuration diagram of a third cooling circuit in the cooling system shown in fig. 1.

Description of reference numerals:

a first cooling circuit 1; a first fluid line 11; a first fluid branch 11 a; a first water supply pipe 111; a first return pipe 112; a first branch radiator 11 b; a first branch regulator valve VV 1; a first branch temperature sensor TT 1; a first branch flow sensor FF 1; a first heat dissipation unit 113; a first valve V1; a first drain valve LV 1; a first exhaust valve AV 1; a first pressure monitoring device P1;

a second cooling circuit 2; a second fluid line 21; a main path 211; a second water supply pipe 211 a; a second water return pipe 211 b; a second fluid branch 2111; a second bypass radiator 2112; a bypass 212; bypass regulator valve 212 a; a second heat dissipation unit 213; second total flow sensor F21; a second front total temperature sensor T21, a second middle total temperature sensor T22; a second rear total temperature sensor T23; a second valve V2; a second drain valve LV 2; a second exhaust valve AV 2; a second pressure monitoring device P2;

a third cooling circuit 3; a third fluid line 31; a first segment 311; a second section 312; a third fluid branch 3121; a third branch radiator 3122; a third heat dissipation unit 313; a heater H; a third total flow sensor F3; a third front total temperature sensor T31; a third medium temperature sensor T32; a third rear total temperature sensor T33; the third branch regulating valve VV 3; a third branch temperature sensor TT 3; a third branch flow sensor FF 3; a third valve V3; a third drain valve LV 3; a third exhaust valve AV 3; a third pressure monitoring device P3;

a first heat exchanger 4; a first inlet port 41 a; a first outlet end 41 b; a second inlet end 42 a; a second outlet end 42 b; a third inlet end 43 a; a third outlet end 43 b;

a second heat exchanger 5; a fourth inlet port 51 a; a fourth outlet port 51 b; a fifth inlet port 52 a; a fifth outlet end 52 b;

a first pump group 12; a second pump group 22; a third pump group 32; a pump body Pu; a pump body regulating valve PV; a check valve SV; a voltage stabilizer SP;

a first heat-generating component 100; a second heat-generating component 200; a third heat generating component 300.

Detailed Description

Features and exemplary embodiments of various aspects of the present invention will be described in detail below. In the following detailed description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. The following description of the embodiments is merely intended to provide a better understanding of the present invention by illustrating examples of the present invention. In the drawings and the following description, at least some well-known structures and techniques have not been shown in detail in order to avoid unnecessarily obscuring the present invention; also, the dimensions of some of the structures may be exaggerated for clarity. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

The following description is given with reference to the orientation words as shown in the drawings, and is not intended to limit the specific structure of the present invention. In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "mounted" and "connected" are to be interpreted broadly, e.g., as being either fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected. The specific meaning of the above terms in the present invention can be understood as appropriate to those of ordinary skill in the art.

With the rapid development of wind generating sets, the single-machine capacity of the set is continuously increased, on one hand, the loss of the set is increased, and on the other hand, the number of parts needing heat dissipation is increased. Particularly, with the development of an E-TOP layout structure of an offshore large-capacity unit, heat generating components such as a generator, a shafting, a pitch system, a nacelle cabinet, a converter cabinet and a transformer are uniformly distributed in the nacelle, but the heat generating components need to be independently subjected to necessary heat dissipation and cooling treatment, so that the number of cooling subsystems in the nacelle is increased, and the structure of each cooling subsystem is also complicated. In view of the difference of control strategies, processes, layout positions and the like of the cooling subsystems, the refrigeration capacity distribution of the heating components is prone to generate large deviation in the actual operation process, the system power consumption is large, and the overall layout and structure optimization of the cooling subsystems of the heating components of the wind generating set are urgently needed to reasonably utilize and distribute the heat and refrigeration capacity of the system.

The invention aims to construct a multi-path coupling cooling system of a wind generating set, and is particularly suitable for an E-TOP layout permanent magnet direct-drive wind generating set with high power on the sea. For the units which are not in the E-TOP layout, that is, the units in which all main heat generating components are not located in the cabin, if the complexity of the pipelines is not considered, the multi-path coupling cooling system of the present application may also be adopted, that is, the cooling subsystems of the heat generating components may be arranged according to the actual positions of the heat generating components by using the same arrangement concept, and the overall arrangement of the cooling subsystems of the heat generating components is optimized. For better understanding of the present invention, a cooling system and a wind turbine generator set according to an embodiment of the present invention will be described in detail with reference to fig. 1 to 4.

Referring to fig. 1, an embodiment of the present invention provides a wind turbine generator system, including: a first heat-generating component 100, a second heat-generating component 200, a third heat-generating component 300, and a cooling system.

The first heat generating component 100 is a combination of components with smaller heat generating amount, and has smaller heat dissipation loss, and the heat dissipation subsystems of the heat generating components can be integrated into one cooling circuit or several cooling branches in an integrated manner, so as to meet the heat dissipation requirements of the heat generating components. Optionally, the first heat-generating component 100 may comprise at least one of a shafting, a cable, a nacelle, a pitch, a nacelle cabinet, a nacelle base.

The second heat generating component 200 is a combination of components with a large heat generation amount, and the heat dissipation loss requirement is also large. Optionally, the second heat generating component 200 may comprise a generator. In addition, the second heat generating component 200, which is exemplified by a generator, not only generates a large amount of heat, but also generates waste heat to be supplied to other heat generating components in a low temperature environment, thereby satisfying the lowest temperature operation requirement of other heat generating components in a low temperature environment.

The third heat generating component 300 is a combination of components having a large heat generation amount, and has a heat generation amount larger than that of the first heat generating component 100 but smaller than that of the second heat generating component 200. Optionally, the third heat generating component 300 may include at least one of a transformer, a current transformer, and an auxiliary transformer. The third heat generating component 300 generally needs to maintain the minimum temperature requirement, and the increase and decrease of the heat dissipation loss thereof is proportional to the heat dissipation loss of the second heat generating component 200, such as a generator, that is, the two components run in opposite directions.

It should be noted that, in practical operation and design, the present invention can perform similar arrangement and coupling arrangement on the cooling circuits according to the specific number of the heat generating components, different cooling forms and cooling requirements, so as to form an integrated cooling system. For convenience of description, the embodiment of the present invention will be described by taking as examples a first cooling circuit 1 (i.e., a small-capacity cooling system) for cooling the first heat-generating component 100, a second cooling circuit 2 (i.e., a generator cooling system) for cooling the second heat-generating component 200, and a third cooling circuit 3 (i.e., an electric cooling system) for cooling the third heat-generating component 300.

The embodiment of the invention provides a cooling system, which comprises: a first cooling circuit 1, a second cooling circuit 2, a third cooling circuit 3, a first heat exchanger 4 and a second heat exchanger 5.

The first cooling circuit 1 includes a first fluid line 11 for cooling the first heat generating component 100 and a first pump group 12, the first pump group 12 being configured to circulate a first cooling medium within the first fluid line 11. The first cooling circuit 1 communicates with a first heat exchanger 4.

The second cooling circuit 2 comprises a second fluid circuit 21 for cooling the second heat generating component 200 and a second pump group 22, the second fluid circuit 21 comprising a main circuit 211 and a bypass 212; the second pump stack 22 is designed to circulate the second cooling medium in the main circuit 211 or in the main circuit 211 and the bypass 212. The main path 211 communicates with the first heat exchanger 4 and the bypass path 212 communicates with the second heat exchanger 5.

The third cooling circuit 3 comprises a third fluid line 31 for cooling the third heat-generating component 300 and a third pump stack 32, the third pump stack 32 being configured to circulate a third cooling medium in the third fluid line 31. The third fluid line 31 communicates with both the first heat exchanger 4 and the second heat exchanger 5. The first heat generating component 100 generates the smallest amount of heat, the second heat generating component 200 generates the largest amount of heat, and the third heat generating component 300 generates the amount of heat between the first heat generating component 100 and the second heat generating component 200.

The first heat exchanger 4 is configured to thermally couple the first cooling medium, the second cooling medium, and the third cooling medium in isolation from each other. The first cooling medium, the second cooling medium, and the third cooling medium may be the same liquid medium, such as water, oil, or the like, or may be different liquid media. Optionally, the first heat exchanger 4 is a liquid-liquid three-way heat exchanger.

The second heat exchanger 5 is configured to thermally couple the second cooling medium and the third cooling medium in isolation from each other by a bypass 212. Optionally, the second heat exchanger 5 is a liquid-liquid two-way heat exchanger.

The cooling system provided by the embodiment of the invention comprises a first cooling circuit 1, a second cooling circuit 2 and a third cooling circuit 3 which are independently operated, and a first heat exchanger 4 and a second heat exchanger 5. The first cooling medium in the first cooling circuit 1, the second cooling medium in the second cooling circuit 2 and the third cooling medium in the third cooling circuit 3 are thermally coupled in isolation from each other by a liquid-liquid three-way first heat exchanger 4. On the other hand, when the temperature control demand of the first heat generating component 100 of the small-capacity cooling system is satisfied under appropriate ambient temperature conditions, the first heat exchanger 4 can distribute the surplus cooling load of the first cooling circuit 1 to the generator cooling system of the second cooling circuit 2 and the electric cooling system of the third cooling circuit 3, thereby making it possible to sufficiently utilize the cooling capacity. In the second aspect, for the generator cooling system, surplus cold energy from the small-capacity cooling system is received through the first heat exchanger 4, and therefore the over-generation of the unit is achieved or the frequency conversion energy conservation of a rotating component at the tail end of the unit is achieved. In the third aspect, the first heat exchanger 4 is used to achieve thermal equilibrium among the small-capacity cooling system, the generator cooling system, and the electric cooling system. Meanwhile, through the second heat exchanger 5 with two liquid-liquid paths, the second cooling medium in the bypass 212 of the second cooling circuit 2 and the third cooling medium in the third cooling circuit 3 are mutually isolated and thermally coupled, so that part of the residual heat carried by the second cooling circuit 2 is used for heating the third cooling circuit 3, and the reasonable application of the residual heat is realized. The cooling system meets the heat dissipation requirement, realizes the balanced utilization of cold and heat through mutual isolation and geothermal coupling among cooling loops, and reduces the power consumption of the system.

Referring again to fig. 1, the bypass 212 is provided with a bypass adjustment valve 212a, and when the temperature of the third cooling medium is lower than the preset temperature, the bypass adjustment valve 212a is opened to allow the second cooling medium in the bypass 212 to exchange heat with the third cooling medium through the second heat exchanger 5.

Therefore, under the condition of extremely low temperature, the generator cooling system transfers the heat load generated by part of loss to the electric cooling system through the bypass 212 by the second heat exchanger 5, thereby not only reasonably utilizing the waste heat of the generator, but also meeting the requirement of the lowest operating temperature of heat generating components such as transformers, converters, auxiliary transformers and the like of the electric cooling system.

Further, the first heat exchanger 4 includes a first heat conduction channel, a second heat conduction channel and a third heat conduction channel which are arranged at intervals. The first heat transfer channel includes a first inlet end 41a and a first outlet end 41b, a first water supply pipe 111 of the first fluid pipe 11 is connected to the first inlet end 41a, and a first water return pipe 112 is connected to the first outlet end 41 b.

The second heat transfer passage includes a second inlet end 42a and a second outlet end 42b, a second water supply pipe 211a of the second fluid pipe 21 is connected to the second inlet end 42a, and a second water return pipe 211b is connected to the second outlet end 42 b.

The third thermally conductive path includes a third inlet end 43a and a third outlet end 43b, and the third fluid line 31 includes a first segment 311 and a second segment 312 extending between the first heat exchanger 4 and the second heat exchanger 5; the third pump group 32 is located in the first section 311, upstream of the first section 312 being connected to the third inlet port 43a and downstream of the second section 312 being connected to the third outlet port 43 b.

Therefore, the first heat exchanger 4 is provided with six interfaces, and the first cooling medium, the second cooling medium and the third cooling medium realize heat transfer in the first heat exchanger 4 in a concurrent flow or cross flow mode, so that heat transfer and balance among the three cooling loops are realized. The six ports may be disposed on the same side of the first heat exchanger 4, or may be disposed on both sides of the first heat exchanger 4.

The second heat exchanger 5 comprises a fourth heat conduction channel and a fifth heat conduction channel which are arranged at intervals.

The fourth heat transfer passage includes a fourth inlet port 51a and a fourth outlet port 51b, a second bypass water supply pipe 212a of the bypass 212 of the second fluid line 21 is connected to the fourth inlet port 51a, and a second bypass water return pipe 212b of the bypass 212 is connected to the fourth outlet port 51 b.

The fifth thermally conductive path includes a fifth inlet end 52a and a fifth outlet end 52b, with the first segment 311 of the third fluid line 31 connected downstream to the fifth inlet end 52a and the second segment 312 connected upstream to the fifth outlet end 52 b.

Therefore, the second heat exchanger 5 is provided with four interfaces, and the second cooling medium and the third cooling medium realize heat transfer in the second heat exchanger 5 in a concurrent flow or cross flow mode, so that heat transfer and balance of two cooling loops are realized. The four ports may be disposed on the same side of the second heat exchanger 5, or may be disposed on both sides of the second heat exchanger 5.

The specific structure of each cooling circuit will be further described in detail with reference to fig. 2 to 4.

Fig. 2 shows a specific structure of the first cooling circuit 1. The first cooling circuit 1 is a small-capacity cooling system including a first fluid line 11, a first pump group 12, a plurality of parallel first branch radiators 11b for cooling the first heat generating component 100, and a first heat radiating unit 113 for taking away heat loss of all components; and the system also comprises functional valves, sensors, a pressure stabilizer and a filter to realize normal, stable and maintainable operation of the first cooling circuit 1.

The first cooling medium flows in from the first heat conduction channel of the first heat exchanger 4, and is conveyed to the plurality of first branch heat exchangers 11b connected in parallel through the first pump group 12, after heat exchange is performed between each branch heat exchanger and each first heating component 100, the first cooling medium flows into the first heat dissipation unit 113, and flows into the first heat conduction channel of the first heat exchanger 4.

In particular, the first pump group 12 comprises one pump body Pu or at least two pump bodies Pu arranged in parallel. When the first pump group 12 includes at least two pump bodies Pu arranged in parallel, the at least two pump bodies Pu can be operated in parallel, or a partial operation and partial standby mode can be adopted, and energy-saving and fault-tolerant operation is realized after comprehensive consideration is given to factors such as spatial arrangement size, system capacity condition, reliability, cost performance and the like, that is, after one pump body Pu breaks down, the rest pump bodies Pu can still meet the performance of the system or more than 75%. Meanwhile, in order to further realize optimal system energy efficiency, the first pump group 12 can adopt control modes such as fixed-frequency operation, high-low-speed operation, variable-frequency operation or fault-tolerant operation of at least two pump bodies Pu, so that the cold load operation requirement of the first cooling circuit 1 is met, and the fault tolerance and the effective energy-saving strategy of the system are improved.

Each pump block is provided with an exhaust valve AV, which exhausts the gas during operation of the system, thus protecting the safe operation of the first pump group 12. The outlet of each pump body Pu is respectively provided with a check valve SV for protecting the pump body Pu; the inlet of each pump body Pu is respectively provided with a pump body regulating valve PV, and when any one pump body Pu has a leakage problem, the corresponding pump body regulating valve PV is quickly closed; the corresponding pump body Pu is cut off by the check valve SV and the pump body regulating valve PV. If the pump body Pu is in a non-mechanical seal mode, the arrangement of the pump body regulating valve PV can be omitted.

Optionally, the inlets of the first pump group 12 are respectively provided with a pressure stabilizer SP for generating alarm and causing damage to the system due to system pressure fluctuation caused by temperature change, and the pressure stabilizer SP can be in the form of a high-level water tank or an expansion tank.

Further, the first fluid pipeline 11 is provided with a plurality of first fluid branches 11a corresponding to the plurality of first heat generating components 100 one to one, the plurality of first heat generating components 100 may be, for example, a shafting, a nacelle, a pitch, and the like, each first fluid branch 11a is provided with a first branch radiator 11b, a first branch regulating valve VV1, a first branch temperature sensor TT1, and a first branch flow sensor FF1 are disposed downstream of each first fluid branch 11a, and the first return pipe 112 of the first fluid pipeline 11 is further provided with a first heat radiating unit 113.

The specific number of the first fluid branches 11a is set according to the number of the first heat-generating components 100. The first cooling medium having passed through the plurality of first fluid branches 11a increases in temperature and enters the first heat radiating unit 113 along the first water supply pipe 111.

The measurement values of the respective first branch temperature sensors TT1 and the respective first branch flow rate sensors FF1 are monitored, and the flow rate of the respective first fluid branches 11a is adjusted by controlling the opening degree of the respective first branch regulating valves VV1 in accordance with the target temperature values of the respective first heat-generating components 100.

The opening degree is adjusted according to the target temperature value of each first heat-generating component 100, so that the heat exchange amount requirement of each first heat-generating component 100 can be met. The first branch regulating valve VV1 can avoid the problems that the loss values of the first fluid branches 11a are different, the calculation process is prone to deviation, and the flow rate is prone to unevenness.

Optionally, at least one of the inlet and outlet of the first pump group 12, the first water supply pipe 111 and the first water return pipe 112 of the first fluid circuit 11, the outlet of the first pump group 12 and upstream and downstream of each first fluid branch 11a is provided with a first valve V1. By closing the first valve V1, replacement and maintenance of the respective components of the first fluid branch 11a can be performed.

Optionally, at least one of the first fluid line 11 and each first fluid branch 11a is further provided with a first drain valve LV1 for local drainage during maintenance and replacement of parts.

Optionally, a first filter is provided at the inlet of the first pump group 12 for ensuring the cleanliness of the system. In addition, the first filter has a liquid discharge function and can be used as a local liquid discharge point of the first pump unit 12.

Optionally, the first pump group 12 and the first heat dissipation unit 113 are respectively provided with a first exhaust valve AV1, the first heat dissipation unit 113 is configured to take away heat loss of all components, and realize local or high exhaust through the first exhaust valve AV1, and the first cooling medium passing through the first heat dissipation unit 113 brings the first cooling medium into the first heat exchanger 4 under the action of the first pump group 12.

Optionally, at least one of the inlet and outlet of the first pump stack 12, upstream and downstream of each first fluid branch 11a, is provided with a first pressure monitoring device P1. Optionally, the first pressure detecting device P1 includes a first pressure transmitter for local and remote monitoring of the system operation condition and a first pressure display device for local liquid injection and operation and maintenance observation.

Fig. 3 shows a specific structure of the second cooling circuit 2. The second cooling circuit 2 is a generator cooling system, and includes a second fluid pipeline 21, a second pump group 22, a plurality of second branch radiators 2112 connected in parallel for cooling the second heat generating component 200, and a second heat dissipation unit 213 for removing heat loss of all components; and also comprises functional valves, sensors, a pressure stabilizer and a filter, so as to realize normal, stable and maintainable operation of the second cooling circuit 2.

The second cooling medium flows in from the second heat conduction path of the first heat exchanger 4, is delivered to the plurality of second bypass heat exchangers 2112 connected in parallel via the second pump group 22, and after each bypass heat exchanger exchanges heat with the second heat generating component 200, when the bypass adjustment valve 212a on the bypass 212 is opened, the second cooling medium respectively flows into the second heat dissipation unit 213 from the main path 211 and the bypass 212, and flows into the second heat conduction path of the first heat exchanger 4.

Wherein the second cooling medium entering the bypass 212 flows through the fourth heat conducting channel of the second heat exchanger 5, exchanges heat with the third cooling medium, and then merges with the main path 211. When the bypass regulating valve 212a on the bypass 212 is closed, the second cooling medium directly enters the second heat radiating unit 213 from the main path 211 and flows into the second heat conducting path of the first heat exchanger 4.

In particular, the second pump group 22 comprises one pump body Pu or at least two pump bodies Pu arranged in parallel. When the second pump group 22 includes at least two pump bodies Pu arranged in parallel, the at least two pump bodies Pu may be operated in parallel, or may be in a partial operation or partial standby mode, and energy-saving and fault-tolerant operation is achieved after comprehensive consideration is given to factors such as spatial arrangement size, system capacity, reliability, cost performance and the like, that is, after one pump body Pu fails, the rest pump bodies Pu still can meet all or more than 75% of the performance of the system. Meanwhile, in order to further realize the optimal energy efficiency of the system, the second pump group 22 may adopt control modes such as fixed-frequency operation, high-low-speed operation, variable-frequency operation or fault-tolerant operation of at least two pump bodies Pu, so as to meet the cold load operation requirement of the second cooling circuit 2, and improve the fault tolerance of the system and an effective energy-saving strategy.

The pump body is provided with an exhaust valve AV which exhausts the gas during operation of the system, thereby protecting the safe operation of the first pump group 12. The outlets of the pump bodies Pu are respectively provided with check valves SV for protecting the pump bodies Pu; the inlets of the pump bodies Pu are respectively provided with pump body regulating valves PV, and when any one of the pump bodies Pu has a leakage problem, the corresponding pump body regulating valve PV is quickly closed; the corresponding pump body Pu is cut off by the check valve SV and the pump body regulating valve PV. If the pump body Pu is in a non-mechanical seal mode, the arrangement of the pump body regulating valve PV can be omitted.

Optionally, the inlet of the second pump stack 22 is provided with a pressure stabilizer SP for stabilizing the system pressure.

Optionally, a second filter is provided at the inlet of the second pump group 22 for ensuring the cleanliness of the system. In addition, the second filter has a drainage function, which can serve as a local drainage point for the second pump stack 22.

Further, the main pipe 211 of the second fluid pipeline 21 is provided with a plurality of second fluid branches 2111 corresponding to the second heat generating component 200, the second heat generating component 200 may be, for example, a generator, the bypass 212 is disposed downstream of the plurality of second fluid branches 2111, each second fluid branch 2111 is provided with a second branch radiator 2112, and the second return pipe 211b of the main pipe 211 is further provided with a second heat radiating unit 213. Since the flow rates and heat exchange amounts of the plurality of second fluid branches 2111 are uniformly arranged, there is no need to provide a relevant flow rate adjustment measure.

The second cooling medium flowing through the second heat dissipation unit 213 enters the first heat exchanger 4, absorbs surplus cooling capacity in the first cooling circuit 1 and realizes balanced distribution of cooling capacity with the third cooling circuit 3, so as to avoid deviation in heat dissipation calculation, and after sufficient heat is achieved, the second branch radiators 2112 and the second pump group 22 can be controlled through frequency conversion or high and low speed means, so that the purpose of energy saving is achieved, or under the conditions of surplus cooling capacity and satisfied wind conditions, the over-sending of the unit is realized.

In addition, the main path 211 is further provided with a second total flow sensor F21 located at the inlet of the second pump group 22, a second front total temperature sensor T21 located at the outlet of the second pump group 22, a second middle total temperature sensor T22 located downstream of the plurality of second fluid branches 2111, and a second rear total temperature sensor T23 located at the inlet of the second heat radiating unit 213.

The total heat dissipation loss of the second fluid pipeline 21 is obtained according to the temperature difference between the second middle total temperature sensor T22 and the second front total temperature sensor T21 and the flow rate of the second total flow sensor F21. In addition, the real-time loss change of the second cooling circuit 2 according to the change of the ambient temperature can be calculated, so that the accumulated data of the system can be optimized conveniently.

The amount of heat to be dissipated in the second fluid pipeline 21 before entering the second heat dissipating unit 213 is obtained according to the temperature difference between the second rear total temperature sensor T23 and the second middle total temperature sensor T22 and the flow rate of the second middle total flow sensor F22. The waste heat quantity transferred from the bypass 212 to the third cooling circuit 3 is obtained according to the difference between the total heat dissipation loss and the heat to be dissipated.

Optionally, at least one of the inlet and outlet of the second pump stack 22, downstream of the plurality of second fluid branches 2111 and upstream and downstream of the bypass 212 is provided with a second pressure monitoring device P2. Optionally, the second pressure detecting device P2 includes a second pressure transmitter and a second pressure display device, the second pressure transmitter is used for monitoring the system operation status locally and remotely, and the second pressure display device is used for local liquid injection and operation and maintenance observation.

A second pressure monitoring device P2 is provided on the bypass 212 entering the second heat exchanger 5, so as to remotely and locally determine the blockage of the second heat exchanger 5 and the second cooling circuit 2 for early replacement and maintenance. Second valves V2 are provided upstream and downstream of the bypass 212 to allow the second heat exchanger 5 to be switched out of the system to meet maintenance requirements.

Optionally, at least one of the second water supply pipe 211a, the second water return pipe 211b, the outlet of the second pump group 22, the upstream and downstream of each second fluid branch 2111, the upstream and downstream of the bypass 212, and the inlet of the second heat radiating unit 213 is provided with a second valve V2.

The second cooling medium of high temperature enters the second heat radiating unit 213, and the second heat radiating unit 213 is provided with a second exhaust valve AV2 for exhausting the high point and part of the second heat radiating unit 213. The inlet of the second heat radiating unit 213 and the second water return pipe 211b are provided with a second valve V2, so that the second heat radiating unit 213 can be cut out to facilitate replacement and maintenance of the second heat radiating unit 213.

The second water supply pipe 211a and the second water return pipe 211b of the second cooling circuit 2 are respectively provided with a second valve V2, so that the parts of the main pipe 211 and the bypass 212 and the second branch radiators 2112 of the second fluid branches 2111 can be easily cut out, and the first heat exchanger 4 can be cut out from the second cooling circuit 2. A second valve V2 is provided in each second fluid branch 2111, and the second branch radiator 2112 can be cut out of the second cooling circuit 2.

Optionally, at least one of the second fluid line 21, each second fluid branch 2111 and each second branch radiator 2112 is provided with a second drain valve LV 2. The second cooling medium in the first heat exchanger 4, the second cooling circuit 2 side, and the second heat radiating unit 213 can be partially discharged by the second drain valve LV 2.

Optionally, at least one of the second pump stack 22, the second fluid line 21, the second heat radiating unit 213 and each second bypass radiator 2112 is provided with a second exhaust valve AV 2. The second branch radiator 2112 is provided with a second exhaust valve AV2 and a second drain valve LV2 respectively, which facilitates the exhaust in the liquid filling process and the exhaust in the maintenance and replacement process of the second branch radiator 2112.

Fig. 4 shows a specific structure of the third cooling circuit 3. The third cooling circuit 3 is an electric cooling system, and includes a third fluid pipe 31, a third pump group 32, a plurality of third branch radiators 3122 connected in parallel for cooling the third heat generating component 300, and a third heat dissipating unit 313 for removing heat loss from all components, and further includes a heater, functional valves, sensors, a pressure stabilizer, and a filter, so as to implement normal, stable, and maintainable operation of the third cooling circuit 3.

The third cooling medium flows in from the third heat conduction channel of the first heat exchanger 4, and is conveyed to the plurality of third branch heat exchangers 3122 in parallel after flowing through the fifth heat conduction channel of the second heat exchanger 5 via the third pump group 32, and after exchanging heat with the third heat generating component 300, each branch heat exchanger converges into the third heat dissipation unit 313, and flows into the third heat conduction channel of the first heat exchanger 4.

In particular, the third pump group 32 comprises one pump body Pu or at least two pump bodies Pu arranged in parallel. When the third pump group 32 includes at least two pump bodies Pu arranged in parallel, the at least two pump bodies Pu can be operated in parallel, or a partial operation and partial standby mode can be adopted, and energy-saving and fault-tolerant operation is realized after comprehensive consideration is given to factors such as spatial arrangement size, system capacity condition, reliability and cost performance, that is, after one pump body Pu breaks down, the rest pump bodies Pu can still meet the performance of the system or more than 75%. Meanwhile, in order to further realize optimal system energy efficiency, the third pump group 32 can adopt control modes such as fixed-frequency operation, high-low-speed operation, variable-frequency operation or fault-tolerant operation of at least two pump bodies Pu, so that the cold load operation requirement of the third cooling circuit 3 is met, and the fault tolerance and the effective energy-saving strategy of the system are improved.

The pump body is provided with an exhaust valve AV to exhaust gas during system operation, thereby protecting the safe operation of the third pump group 32. The outlets of the pump bodies Pu are respectively provided with check valves SV for protecting the pump bodies Pu; the inlets of the pump bodies Pu are respectively provided with pump body regulating valves PV, and when any one of the pump bodies Pu has a leakage problem, the corresponding pump body regulating valve PV is quickly closed; the corresponding pump body Pu is cut off by the check valve SV and the pump body regulating valve PV. If the pump body Pu is in a non-mechanical seal mode, the arrangement of the pump body regulating valve PV can be omitted.

Optionally, the inlet of the third pump group 32 is provided with a pressure stabilizer SP for stabilizing the system pressure.

Further, a third total flow sensor F3 is disposed upstream of the first section 311 of the third fluid line 31, a third front total temperature sensor T31 is disposed downstream of the first section 311, and a third heat dissipation unit 313 is disposed downstream of the second section 312.

According to the difference of the number of the third heat generating components 300 and the heat dissipation loss, the second section 312 is provided with a plurality of third fluid branches 3121 corresponding to the plurality of third heat generating components 300 one by one, the plurality of third heat generating components 300 may be, for example, a transformer, a current transformer, an auxiliary transformer, etc., each third fluid branch 3121 is provided with a third branch radiator 3122, and a third branch regulating valve VV3, a third branch temperature sensor TT3 and a third branch flow sensor FF3 are disposed downstream of each third fluid branch 3121.

The measured values of each third branch temperature sensor TT3 and each third branch flow sensor FF3 are monitored, and the flow rate of each third fluid branch 3121 is adjusted by controlling the degree of opening of each third branch regulating valve VV3 in accordance with the target temperature value of each third heat-generating component 300.

Further, a heater H is provided downstream of the first section 311 of the third fluid line 31, and the heater H is activated when the temperature of the third cooling medium is lower than a preset temperature and the second heat generating component 200 is not activated.

Since the third heat generating component 300, i.e. the converter, cannot be started at very low temperatures, preheating by the cooling medium in the third cooling circuit 3 is required. If the second heat generating component 200, i.e. the generator, is not in start-up operation, the converter can heat the cooling medium by starting the heater H to meet the preheating requirement before the converter is started. If the generator is started during this time, the heater H is switched off and the bypass regulating valve 212a is opened, and the waste heat generated by the generator can heat the cooling medium in the second cooling circuit 2 and enter the second heat exchanger 5 through the bypass 212. The third cooling medium of low temperature exchanges heat with the second cooling medium of high temperature in the second heat exchanger 5 until a preset temperature is reached at which the converter can be started. When the temperature of the third cooling medium reaches a preset temperature, the inverter starts to operate, and the bypass adjustment valve 212a is closed. The self-consumption power of the system can be saved and the energy consumption of the system can be reduced by recycling the waste heat of the generator and starting the heater H as little as possible.

Optionally, a third intermediate total temperature sensor T32 is further disposed upstream of the second segment 312, and the opening/closing of the heater H and the opening of the bypass regulating valve 212a are controlled according to the measurement value of the third intermediate total temperature sensor T32, so as to meet the system requirement. The flow rate of the high-temperature cooling medium entering the bypass 212 is adjusted by controlling the opening degree of the bypass adjustment valve 212a, thereby gradually heating the third cooling medium.

The third cooling medium after temperature rise enters the third heat dissipation unit 313, enters the first heat exchanger 4 again after heat dissipation, absorbs surplus cold in the first cooling circuit 1, and simultaneously realizes balanced distribution of heat with the second cooling circuit 2, thereby achieving the effect of energy saving or over-heating of the third pump group 32.

Further, a third rear total temperature sensor T33 is disposed downstream of the second section 312, and the heat exchange amount of the third cooling medium after flowing through the first heat exchanger 4 is obtained according to the temperature difference between the third rear total temperature sensor T33 and the third front total temperature sensor T31 and the flow rate of the third total flow sensor F3. The total heat generation amount of the third heat generating component 300 is obtained according to the temperature difference between the third rear total temperature sensor T33 and the third middle total temperature sensor T32 and the flow rate of the third total flow rate sensor F3.

Optionally, at least one of upstream and downstream of the first section 311, upstream and downstream of the second section 312, upstream and downstream of each third fluid branch 3121 and the inlet of the third heat sink unit 313 is provided with a third valve V3.

Optionally, at least one of the first segment 311, each third fluid branch 3121 is provided with a third drain valve LV 3. Optionally, a third filter is provided at the inlet of the third pump group 32 to ensure the cleanliness of the system. In addition, the third filter has a drainage function and can serve as a local drainage point of the third pump group 32.

Optionally, at least one of the third pump stack 32, the third heat dissipation unit 313 and each third fluid branch 3121 is provided with a third venting valve AV 3.

The third valve V3, the third drain valve LV3 and the third exhaust valve AV3 are similar to the second valve V2, the second drain valve LV2 and the second exhaust valve AV2 in function, and are not described again.

Optionally, at least one of the inlet and outlet of the third pump stack 33, downstream of the first section 311, upstream of the second section 312 and upstream and downstream of each third fluid branch 3121 is provided with a third pressure monitoring device P3. Optionally, the third pressure detecting device P3 includes a third pressure transmitter and a third pressure display device, the third pressure transmitter is used for monitoring the system operation status locally and remotely, and the third pressure display device is used for local liquid injection and operation and maintenance observation.

Therefore, in the cooling system provided by the embodiment of the invention, the first cooling circuit 1, the second cooling circuit 2 and the third cooling circuit 3 form respective closed-loop cycles through pipelines, valves, temperature sensors, flow sensors, pressure transmitters and the like, and under the condition of keeping the independent operation of the cooling circuits, the first heat exchanger 4 and the second heat exchanger 5 conduct heat transfer and mass transfer on the cooling circuits, so that the reasonable distribution of cooling capacity of multiple systems is realized, and the heat dissipation requirements of heat generating components are met. Meanwhile, the cooling loops are internally provided with regulating valves, the flow of each cooling loop is regulated according to the load requirements of each heat generating component, the surplus cold energy is distributed to the second cooling loop 2 and the third cooling loop 3 under the condition of meeting the temperature control requirement of the first heat generating component 100 of the first cooling loop 1 under the condition of proper environmental temperature, part of the surplus heat carried by the second cooling loop 2 is used for heating the third cooling loop 3 through the bypass 212, the power consumption caused by electric heating of the third cooling loop 3 is reduced, and the reasonable distribution of the cold energy and the reasonable application of the surplus heat are realized through mutual isolation geothermal coupling among the cooling loops while the heat dissipation requirement is met, so that the balanced utilization of the cold energy and the heat is realized, and the power consumption of the system is reduced.

In addition, the cooling system provided by the embodiment of the invention can effectively count the system loss and the heat transfer direction in the running process of the wind generating set, and simultaneously can search more reasonable part model selection by combining the environmental temperature, thereby providing sufficient data statistics basis for the subsequent evaluation of the reliability of the wind generating set.

Further, the cooling system according to the exemplary embodiments described above may be applied to various electrical devices that require heat dissipation to be provided, such as, but not limited to, a wind turbine generator set.

While the invention has been described with reference to a preferred embodiment, various modifications may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In particular, the technical features mentioned in the embodiments can be combined in any way as long as there is no structural conflict. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

Claims

1. A cooling system, comprising: a first cooling circuit (1), a second cooling circuit (2), a third cooling circuit (3), a first heat exchanger (4) and a second heat exchanger (5);

the first cooling circuit (1) comprises a first fluid line (11) for cooling a first heat-generating component (100) and a first pump group (12), the first pump group (12) being configured to circulate a first cooling medium within the first fluid line (11);

the second cooling circuit (2) comprises a second fluid line (21) for cooling a second heat generating component (200) and a second pump group (22), the second fluid line (21) comprising a main path (211) and a bypass path (212); the second pump group (22) is designed to circulate a second cooling medium in the main path (211) or in the main path (211) and the bypass path (212);

-the third cooling circuit (3) comprises a third fluid line (31) for cooling a third heat generating component (300) and a third pump stack (32), the third pump stack (32) being configured to circulate a third cooling medium in the third fluid line (31), the third fluid line (31) communicating both the first heat exchanger (4) and the second heat exchanger (5);

the first heat exchanger (4) is configured to thermally couple the first cooling medium, the second cooling medium and the third cooling medium in isolation from each other;

the second heat exchanger (5) is configured to thermally couple the second cooling medium and the third cooling medium in isolation from each other via the bypass (212).

2. The cooling system according to claim 1, characterized in that a bypass regulating valve (212a) is provided on the bypass (212), and when the temperature of the third cooling medium is lower than a preset temperature, the bypass regulating valve (212a) is opened to allow the second cooling medium in the bypass (212) to exchange heat with the third cooling medium through the second heat exchanger (5).

3. The cooling system according to claim 2, wherein the first heat exchanger (4) comprises a first heat conducting channel, a second heat conducting channel and a third heat conducting channel which are arranged at intervals;

the first heat conducting channel comprises a first inlet end (41a) and a first outlet end (41b), a first water supply pipe (111) of the first fluid pipeline (11) is connected with the first inlet end (41a), and a first water return pipe (112) is connected with the first outlet end (41 b);

the second heat conduction channel comprises a second inlet end (42a) and a second outlet end (42b), a second water supply pipe (211a) of the second fluid pipeline (21) is connected with the second inlet end (42a), and a second water return pipe (211b) is connected with the second outlet end (42 b);

the third heat transfer channel comprising a third inlet end (43a) and a third outlet end (43b), the third fluid conduit (31) comprising a first segment (311) and a second segment (312) extending between the first heat exchanger (4) and the second heat exchanger (5); the third pump group (32) is located in the first section (311), upstream of the first section (312) connected to the third inlet end (43a), downstream of the second section (312) connected to the third outlet end (43 b).

4. A cooling system according to claim 3, wherein the second heat exchanger (5) comprises a fourth heat conducting channel and a fifth heat conducting channel arranged at intervals;

the fourth heat conduction channel comprises a fourth inlet end (51a) and a fourth outlet end (51b), a second bypass water supply pipe (212a) of the bypass (212) of the second fluid pipeline (21) is connected with the fourth inlet end (51a), and a second bypass water return pipe (212b) of the bypass (212) is connected with the fourth outlet end (51 b);

the fifth heat conducting channel comprises a fifth inlet end (52a) and a fifth outlet end (52b), the first section (311) of the third fluid line (31) being connected downstream to the fifth inlet end (52a) and the second section (312) being connected upstream to the fifth outlet end (52 b).

5. The cooling system according to claim 3, wherein a plurality of first fluid branches (11a) corresponding to the plurality of first heat generating components (100) are provided on the first fluid pipeline (11), a first branch radiator (11b) is provided on each first fluid branch (11a), a first branch regulating valve (VV1), a first branch temperature sensor (TT1) and a first branch flow sensor (FF1) are provided downstream of each first fluid branch (11a), and a first heat radiating unit (113) is further provided on the first return pipe (112) of the first fluid pipeline (11);

the measured values of each first branch temperature sensor (TT1) and each first branch flow sensor (FF1) are monitored, and the flow rate of each first fluid branch (11a) is adjusted by controlling the opening degree of each first branch regulating valve (VV1) in accordance with the target temperature value of each first heat generating component (100).

6. Cooling system according to claim 5, characterized in that at least one of the first water supply pipe (111) and the first water return pipe (112) of the first fluid circuit (11), the outlet of the first pump group (12) and upstream and downstream of each first fluid branch (11a) is provided with a first valve (V1);

at least one of the first fluid pipeline (11) and each first fluid branch (11a) is further provided with a first liquid discharge valve (LV 1);

at least one of the first pump group (12) and the first heat dissipation unit (113) is provided with a first air exhaust valve (AV 1).

7. Cooling system according to claim 5, characterized in that at least one of the inlet and outlet of the first pump stack (12), upstream and downstream of each of the first fluid branches (11a) is provided with a first pressure monitoring device (P1).

8. The cooling system according to claim 4, wherein a plurality of second fluid branches (2111) corresponding to the second heat generating component (200) are provided on the main path (211) of the second fluid piping (21), the bypass (212) is provided downstream of the plurality of second fluid branches (2111), a second branch radiator (2112) is provided on each second fluid branch (2111), and a second heat radiating unit (213) is further provided on the second return pipe (211b) of the main path (211);

and a second total flow sensor (F21) positioned at the inlet of the second pump group (22), a second front total temperature sensor (T21) positioned at the outlet of the second pump group (22), a second middle total temperature sensor (T22) positioned at the downstream of the second fluid branches (2111) and a second rear total temperature sensor (T23) positioned at the inlet of the second heat dissipation unit (213) are also arranged on the main path (211).

9. The cooling system according to claim 8, characterized in that the total heat dissipation loss of the second fluid line (21) is obtained from the temperature difference between the second medium total temperature sensor (T22) and the second front total temperature sensor (T21) and the flow rate of the second total flow sensor (F21);

obtaining the amount of heat to be dissipated of the second fluid pipeline (21) before entering the second heat dissipation unit (213) according to the temperature difference value between the second rear total temperature sensor (T23) and the second middle total temperature sensor (T22) and the flow rate of the second middle total flow sensor (F22);

and obtaining the residual heat quantity transferred from the bypass (212) to the third cooling loop (3) according to the difference value between the total heat dissipation loss quantity and the to-be-dissipated heat loss quantity.

10. The cooling system according to claim 8, wherein at least one of the second water supply pipe (211a), the second water return pipe (211b), the outlet of the second pump group (22), the upstream and downstream of each of the second fluid branches (2111), the upstream and downstream of the bypass (212), and the inlet of the second heat radiating unit (213) is provided with a second valve (V2);

at least one of the second fluid pipeline (21), each second fluid branch (2111) and each second branch radiator (2112) is provided with a second drain valve (LV 2);

at least one of the second pump stack (22), the second fluid line (21), the second heat dissipation unit (213) and each of the second bypass radiators (2112) is provided with a second exhaust valve (AV 2).

11. A cooling system according to claim 8, characterised in that at least one of the inlet and outlet of the second pump stack (22), downstream of the plurality of second fluid branches (2111) and upstream and downstream of the bypass (212) is provided with a second pressure monitoring device (P2).

12. Cooling system according to claim 4, characterized in that a third total flow sensor (F3) is arranged upstream of the first section (311) of the third fluid line (31), a third front total temperature sensor (T31) is arranged downstream of the first section (311), and a third heat sink unit (313) is arranged downstream of the second section (312);

a plurality of third fluid branch circuits (3121) which are in one-to-one correspondence with the plurality of third heat generating components (300) are arranged on the second section (312), a third branch radiator (3122) is arranged on each third fluid branch circuit (3121), and a third branch regulating valve (VV3), a third branch temperature sensor (TT3) and a third branch flow sensor (FF3) are arranged downstream of each third fluid branch circuit (3121);

the measured values of each third branch temperature sensor (TT3) and each third branch flow sensor (FF3) are monitored, and the flow rate of each third fluid branch (3121) is adjusted by controlling the degree of opening of each third branch regulating valve (VV3) in accordance with the target temperature value of each third heat-generating component (300).

13. A cooling system according to claim 12, characterised in that a heater (H) is arranged downstream of the first section (311) of the third fluid circuit (31), which heater (H) is activated when the temperature of the third cooling medium is below a preset temperature and the second heat generating component (200) is not activated.

14. The cooling system according to claim 13, wherein a third intermediate total temperature sensor (T32) is further provided upstream of the second section (312), and the opening/closing of the heater (H) and the opening degree of the bypass regulating valve (212a) are controlled in accordance with a measurement value of the third intermediate total temperature sensor (T32).

15. The cooling system according to claim 12, wherein a third rear total temperature sensor (T33) is further provided downstream of the second section (312), and a total heat generation amount of the third heat generating component (300) is obtained according to a temperature difference between the third rear total temperature sensor (T33) and the third middle total temperature sensor (T32) and a flow rate of the third total flow sensor (F3);

and obtaining the heat exchange quantity of the third cooling medium after flowing through the first heat exchanger (4) according to the temperature difference value of the third rear total temperature sensor (T33) and the third front total temperature sensor (T31) and the flow quantity of the third total flow sensor (F3).

16. A cooling system according to claim 12, wherein at least one of upstream and downstream of the first section (311), upstream and downstream of the second section (312), upstream and downstream of each of the third fluid branches (3121) and the inlet of the third heat radiating unit (313) is provided with a third valve (V3);

at least one of the first segment (311) and each of the third fluid branches (3121) is provided with a third drain valve (LV 3);

at least one of the third pump stack (32), the third heat dissipation unit (313) and each of the third fluid branches (3121) is provided with a third exhaust valve (AV 3).

17. A cooling system according to claim 12, characterised in that at least one of the inlet and outlet of the third pump stack (33), downstream of the first section (311), upstream of the second section (312) and upstream and downstream of each of the third fluid branches (3121) is provided with a third pressure monitoring device (P3).

18. The cooling system according to claim 1, characterized in that the first pump group (12), the second pump group (22), the third pump group (32) each comprise one pump body (Pu) or at least two pump bodies (Pu) arranged in parallel, the pump bodies (Pu) being provided with exhaust valves (AV), the outlets of the pump bodies (Pu) being provided with check valves (SV), respectively, the inlets of the pump bodies (Pu) being provided with pump body regulating valves (PV), respectively; and the inlets of the first pump group (12), the second pump group (22) and the third pump group (32) are respectively provided with a pressure stabilizing device (SP).

19. A wind turbine generator set, comprising:

a first heat-generating component (100) comprising at least one of a shafting, a cable, a nacelle, a pitch, a nacelle cabinet, a nacelle base;

a second heat generating component (200) comprising a generator;

a third heat generating component (300) comprising at least one of a transformer, a current transformer, an auxiliary transformer;

the cooling system of any one of claims 1-18.